Dave's number one rule of weightlifting: if something hurts other than what is being trained, stop and check your form.
Someone asked me today why their forearm hurt when doing preacher curls. Unfortunately for him I was with a client, so he did not really get my full attention. (That's another blog entirely.)
Had I been able to focus on this lifter, I would have watched him to make sure he did not leave his wrists flexed when doing preacher curls. Flexing makes the grip more strenuous, which in turn causes fatigue in the forearms. If your form is strong, use a narrower bar to lessen the strain of the grip. Conversely, if your forearms need work, go to a thicker bar or dumbbell.
Another question I get on preacher curls is about shoulder pain during the movement.
If this happens, check your shoulders. Do not lean over the preacher bench. Sit squarely in the seat and let your arms do the work.
Earlier in the day I happened to spot a person doing side bends with a 45-pound plate. As he tipped to the side, his torso also bent forward and engaged his abs (and possibly his lower back). He sacrificed good oblique isolation for bad form. There also was a possibility of low back strain.
That brings us to Dave's number two rule of lifting: never give up good form for more weight.
Another issue I saw was kind of interesting and new to me: a client said he was unable to do squats because of knee pain during the motion. When he demonstrated his technique (with very little weight on the bar), I watched his left knee float in and out of position during his squat. When he corrected his stance — which truly was off by less than an inch — he was able to squat a good amount of weight with no knee pain.
These are just a few examples of technique checks I make every day with clients and weightlifters on the floor.
Remember: when trying to do something good for yourself and your body, don't suffer an injury that could have been avoided simply by checking your form. Get what you can out of a training session — and don't miss any because of injury due to carelessness or misunderstanding.